Seven people attempted suicide by drinking a poisonous liquid outside the gates of the China Youth Daily in Beijing yesterday morning, the newspaper said on its social media account.
Pictures circulated online showed five men and two women lying on the pavement outside the newspaper building.
A stream of white foam could be seen running out of one man's mouth in the pictures.
All seven were taken to hospital, and police were investigating the case, the Daily said.
Southern Metropolis Daily reported that the seven had drunk pesticide and were petitioners from Qingyang in Sihong county in eastern Jiangsu province.
Their land was seized by the local government and they were petitioning because they were not satisfied with the compensation the authorities paid, the newspaper said.
"Too many houses were forcibly demolished in Qingyang and a local court has ruled the demolition as illegal," Wang Jinshan, another petitioner from the same town, told the South China Morning Post.
The seven were held in an illegally run detention centre, or "black jail", after they took their petitions to a higher level of government, Southern Metropolis Daily said.
An official from Jiangsu was guarding the emergency room where two of the petitioners were being treated, stopping journalists from going in yesterday, The Beijing News reported.
The injuries the seven suffered were no longer life threatening, according to the newspaper.
Human rights group say that petitioning, which goes back to imperial times, often leads to people with complaints being held in illegal detention centres by the authorities.
People can petition for years without their grievances being addressed and they occasionally resort to extreme measures to draw public attention to their cases.